Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Sulfasalazine is dosed at 15–30 mg/kg PO q8-12h (max 6 g total daily dose) in dogs, per Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted), p.1230 (Sulfasalazine, Dosages, DOGS); corroborated by BSAVA Small Animal Formulary 10th Ed Part A p.388 'Dogs: All uses: 15-30 mg/kg p.o. q8-12h, maximum 6 g/day' — Plumb's 10th ed (held) printed p.1203, Sulfasalazine monograph spanning p.1202-1203; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705; Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 — CEILING: BSAVA Small Animal Formulary, Sulfasalazine, corpus p.404 (printed p.389) — "Dogs: All uses: 15-30 mg/kg p.o. q8-12h, maximum 6 g/day"; and Plumb's, printed p.1230, DOGS/Inflammatory large bowel disease — "Initial dosages range from 15 - 30 mg/kg PO every 8 to 12 hours, not to exceed a total daily dose of 6 g". max_dose_mg is 2000 so that the fastest permitted interval (q8h) cannot exceed 6 g/day.. Sulfasalazine is used in dogs for Inflammatory bowel disease / colitis, Colitis. Routes documented in dogs: PO. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 2 cited dose rules for Sulfasalazine in dogs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Azulfidine
| Route | Dose | Frequency | Duration |
|---|
| Indication |
|---|
| Evidence |
|---|
| Source |
|---|
| PO | 15–30 mg/kgmax 2000 mg total | q8-12h (max 6 g total daily dose) | Initial 4 weeks, then taper | Inflammatory bowel disease / colitis | Strong | Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted), p.1230 (Sulfasalazine, Dosages, DOGS); corroborated by BSAVA Small Animal Formulary 10th Ed Part A p.388 'Dogs: All uses: 15-30 mg/kg p.o. q8-12h, maximum 6 g/day' — Plumb's 10th ed (held) printed p.1203, Sulfasalazine monograph spanning p.1202-1203; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705; Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 — CEILING: BSAVA Small Animal Formulary, Sulfasalazine, corpus p.404 (printed p.389) — "Dogs: All uses: 15-30 mg/kg p.o. q8-12h, maximum 6 g/day"; and Plumb's, printed p.1230, DOGS/Inflammatory large bowel disease — "Initial dosages range from 15 - 30 mg/kg PO every 8 to 12 hours, not to exceed a total daily dose of 6 g". max_dose_mg is 2000 so that the fastest permitted interval (q8h) cannot exceed 6 g/day. |
| PO | 10–30 mg/kgmax 2000 mg total | q8-12h | 4-6 weeks then taper | Colitis | Strong |
Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.
| Dose (mg/kg) | Route | Source | As printed |
|---|---|---|---|
| 15–30 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.404 | 15-30 mg/kg p.o. q8-12h, maximum 6 g/day |
| 10–30 | PO | Papich Saunders Handbook of Veterinary Drugs, 4th edp.784 | • 10-30 mg/kg q8-12h PO. |
Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.
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Cleaved by colonic bacteria to 5-aminosalicylic acid (mesalamine) and sulfapyridine. 5-ASA acts locally to reduce colonic inflammation.
Used for colitis in dogs. KCS (dry eye) risk — monitor Schirmer tear test. Cats: salicylate sensitivity. Folate supplementation recommended. GI upset.
Species-specific contraindications and adverse-reaction reports for dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Sulfasalazine dose ranges in dogs, with cited source references: PO 15–30 mg/kg q8-12h (max 6 g total daily dose); PO 10–30 mg/kg q8-12h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Sulfasalazine in dogs: PO.
Cited course lengths for Sulfasalazine in dogs include: Initial 4 weeks, then taper; 4-6 weeks then taper. Duration depends on the indication — match it to the specific dose rule in the table above.
Sulfasalazine is indicated in dogs for: Inflammatory bowel disease / colitis, Colitis.
These are general warnings for Sulfasalazine across species; consult the dog dosing table above for species-specific guidance. Used for colitis in dogs. KCS (dry eye) risk — monitor Schirmer tear test. Cats: salicylate sensitivity. Folate supplementation recommended. GI upset.
Why a species-specific page? Sulfasalazine pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in dogs — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.